| 摘要 |
In order to provide a technique effective in reasonably constructing an airbag cover for covering a vehicle airbag, an ultrasonic machine 200 is used that includes an ultrasonic machining blade 216 for machining a tear line 102 in the cover rear surface 101 of the airbag cover 100; first and second transmitting displacement sensors 220 and 230 that are disposed on the opposite side of the cover rear surface 101 of the airbag cover 100 so as to be opposed to a cutting edge 216a of the ultrasonic machining blade 216 with the airbag cover 100 interposed therebetween, and that directly sense the distance between the cutting edge 216a and each of the first and second displacement sensors 220 and 230 through the airbag cover 100; and control means 242 for controlling the relative position of the cutting edge 216a with respect to the airbag cover 100, based on the sensed results by the first and second displacement sensors 220 and 230. |
